将c中的.csv文件读入多个变量

我不熟悉C。我必须使用函数从.csv文件中读入三个不同数组的值。函数原型如下所示：

void readUsageFromFile(double usage1[], double usage2[], double usage3[]);

.csv文件的格式如下：

Day,Time,Apartment1,Apartment2,Apartment3
01,00:00,0,0.001,0
01,01:00,0,0,0
01,02:00,0,0,0
...

第一个值是天，第二个值是一天中的时间，第三个值是第一套公寓的用水量，第四个值是第二套公寓的用水量，第五个值是第三套公寓的用水量。这些值表示30天内每个公寓每天每小时的用水量，因此有720行值

所有这些值都在一列中，共有721行，包括标题Day、Time、Apartment1、

我还得到了一个可以用来处理.csv文件的函数，但它只会让我更加困惑。以下是函数：

#define DEBUG 0


void csvToStrings(char *csvString, char *day, char *time, char *usage1, char 
*usage2, char *usage3)
{
    // Declare variables
    int i, j;
    char c;

    if (DEBUG)
        printf("csvToStrings: Length of string is %d\n", strlen(csvString));

    // Read day
    i = 0;
    j = 0;
    c = csvString[i++];
    while (c != ',')
    {
        day[j++] = c;
        c = csvString[i++];
    }
    day[j++] = '\0';
    if (DEBUG)
        printf("csvToStrings: day string: %s\n", day);

    // Read time
    j = 0;
    c = csvString[i++];
    while (c != ',')
    {
        time[j++] = c;
        c = csvString[i++];
    }
    time[j++] = '\0';
    if (DEBUG)
        printf("csvToStrings: time string: %s\n", time);

    // Read usage1
    j = 0;
    c = csvString[i++];
    while (c != ',')
    {
        usage1[j++] = c;
        c = csvString[i++];
    }
    usage1[j++] = '\0';
    if (DEBUG)
        printf("csvToStrings: usage1 string: %s\n", usage1);

    // Read usage2
    j = 0;
    c = csvString[i++];
    while (c != ',')
    {
        usage2[j++] = c;
        c = csvString[i++];
    }
    usage2[j++] = '\0';
    if (DEBUG)
        printf("csvToStrings: usage2 string: %s\n", usage2);

    // Read usage3
    j = 0;
    c = csvString[i++];
    while (c != '\0')
    {
        usage3[j++] = c;
        c = csvString[i++];
    }
    usage3[j++] = '\0';
    if (DEBUG)
        printf("csvToStrings: usage3 string: %s\n", usage3);
}

/*
 * Function to parse a csv line
 * 
 * The function reads the csv line from `csvString` parameter
 * and writes the values to the `day`, `time`, `usage1`, `usage2` and `usage3` parameters
 *
 *
 * Parameters:
 *    csvString - C string. Input. Mandatory
 *        a CSV line. A comma (,) separated list of values
 *        respecting the format:
 *        Day,Time,Apartment1,Apartment2,Apartment3
 *
 *    day - string buffer. output. Mandatory
 *        a preallocated buffer to write the parsed day value to.
 *        the buffer must have a size to fit
 *        the value including the null terminating character
 *
 *    time - string buffer. output. Mandatory
 *        a preallocated buffer to write the parsed time value to.
 *        the buffer must have a size to fit
 *        the value including the null terminating character
 *
 *    usage1-3 - string buffer. output. Mandatory
 *        3 preallocated buffers to write the parsed usage1-3 values to.
 *        the buffers must have a size to fit
 *        the values including the null terminating character
 *
 *        
*/
void csvToStrings(char *csvString, char *day, char *time, char *usage1,
                  char *usage2, char *usage3);

---

其思想是在函数readUsageFromFile中使用函数csvToString（）。我已经看到了如何从.csv文件中读入值的示例，但对于如何将值读入不同的数组并将其分配给正确的数组，我感到困惑。我如何开始呢？

我不会为您解决这个问题。然而，我要做的是编写

csvToStrings

函数的人首先应该做的事情：我要正确地记录函数：

#define DEBUG 0


void csvToStrings(char *csvString, char *day, char *time, char *usage1, char 
*usage2, char *usage3)
{
    // Declare variables
    int i, j;
    char c;

    if (DEBUG)
        printf("csvToStrings: Length of string is %d\n", strlen(csvString));

    // Read day
    i = 0;
    j = 0;
    c = csvString[i++];
    while (c != ',')
    {
        day[j++] = c;
        c = csvString[i++];
    }
    day[j++] = '\0';
    if (DEBUG)
        printf("csvToStrings: day string: %s\n", day);

    // Read time
    j = 0;
    c = csvString[i++];
    while (c != ',')
    {
        time[j++] = c;
        c = csvString[i++];
    }
    time[j++] = '\0';
    if (DEBUG)
        printf("csvToStrings: time string: %s\n", time);

    // Read usage1
    j = 0;
    c = csvString[i++];
    while (c != ',')
    {
        usage1[j++] = c;
        c = csvString[i++];
    }
    usage1[j++] = '\0';
    if (DEBUG)
        printf("csvToStrings: usage1 string: %s\n", usage1);

    // Read usage2
    j = 0;
    c = csvString[i++];
    while (c != ',')
    {
        usage2[j++] = c;
        c = csvString[i++];
    }
    usage2[j++] = '\0';
    if (DEBUG)
        printf("csvToStrings: usage2 string: %s\n", usage2);

    // Read usage3
    j = 0;
    c = csvString[i++];
    while (c != '\0')
    {
        usage3[j++] = c;
        c = csvString[i++];
    }
    usage3[j++] = '\0';
    if (DEBUG)
        printf("csvToStrings: usage3 string: %s\n", usage3);
}

/*
 * Function to parse a csv line
 * 
 * The function reads the csv line from `csvString` parameter
 * and writes the values to the `day`, `time`, `usage1`, `usage2` and `usage3` parameters
 *
 *
 * Parameters:
 *    csvString - C string. Input. Mandatory
 *        a CSV line. A comma (,) separated list of values
 *        respecting the format:
 *        Day,Time,Apartment1,Apartment2,Apartment3
 *
 *    day - string buffer. output. Mandatory
 *        a preallocated buffer to write the parsed day value to.
 *        the buffer must have a size to fit
 *        the value including the null terminating character
 *
 *    time - string buffer. output. Mandatory
 *        a preallocated buffer to write the parsed time value to.
 *        the buffer must have a size to fit
 *        the value including the null terminating character
 *
 *    usage1-3 - string buffer. output. Mandatory
 *        3 preallocated buffers to write the parsed usage1-3 values to.
 *        the buffers must have a size to fit
 *        the values including the null terminating character
 *
 *        
*/
void csvToStrings(char *csvString, char *day, char *time, char *usage1,
                  char *usage2, char *usage3);

另一方面，该功能有几个问题：

• csvString

  应该是

  const char*

• 每个输出缓冲区都应该有一个size参数。 函数应检查越界访问
• 函数应该验证输入
• 解析可以改进。强烈建议使用字符串库函数代替原始

  ，而
  循环和逐字符手动复制

你必须做什么 如您所见，该函数解析CSV行

您需要：

• 逐行读取csv
• 除页眉外的每行
  • 使用

    csvToStrings

    从该行获取每个值
  • 根据需要使用这些值

---

年，我发布了一个基本的CSV解析器。这可能更简单。在这个网站上，“我如何开始这方面的工作？”不是一个好问题。这不是一个辅导网站，也不是一个为您编写代码的网站。当您准备尝试某项功能，但它不起作用时，我们可以帮助您。编写并向您提供

csvToStrings

函数的人应该添加对该函数及其参数的描述。当您传递数组时，你必须提供它的大小以及在该功能。我很抱歉，我不想有人为我写的代码我只是想得到一个提示，我迷路了，并尝试了几个网站。我在这方面的笔记非常有限。